Stencil



May 14 1940 v B. F. WALKER 2,200,314

STENCIL Y Filed May 25, .1938

.,INVENTOR Patented May 14, 1940 sTEN'cIL Bernard F. Walker, Cedarhurst, N. Y., assigner to Metaplast Corporation, NewVV York, N. Y., a corporation of New York Application May 23, 1938, Serial No.209,524

Claims.

ratus for treating the surface of materials and more particularly to a novel and improved stencil adapted for the`treatment of rigid materials, such 5 as metal or plastic compositions.

An object of the invention is to provide a novel and improved stencil of the type above mentioned.

Another object is to provide a stencil which may be usd for applying a design to rigid materials.

Another object is to provide a stencil which requires a minimum quantity of treating fluid for its action. i5 Another object is to provide a stencil which is so arranged and constructed that the treating fluid is caused to flow serially over the various parts to be treated.

Various other objects and advantages will be apparent as the nature of the invention is more fullyy disclosed. Although the novel features which are believed to be characteristic of this invention will be 'more particularly pointed out in the claims appended hereto, the invention itself may be better understood by referring to the following description taken in connection with Vthe accompanying drawing n which a particular embodiment thereof has been set forth for purposes of illustration. In'the drawing:

Fig. 1 is a top plan view with parts broken away of an assembled stencil embodying the present invention;

Fig. 2 is a section taken on the line 2-2 of Fig- 1;

Fig. 3 is a detail view of an object showing the completed design stencled on the surface thereof; Fig. 4 is a perspective view of the stencil base; Fig. 5 is a perspective view of the stencil cover; and

Fig. 6 is a perspective view of the top plate used for completing the assembly.

In the following description and in the claims certain specific terms areI used for convenience inreferring to various details of the invention.

These terms are to be given as broad an interpretation as the state of the art will permit.

Referring to the drawing more in detail, the invention is shown as applied to an apparatus for producingI a design, comprising a lpair of concentric rectangles Ill and II on the surface of a sheet I2 of rigid material, such as metal, plastic compositions or the like. In the embodiment shown the concentric rectangles I 0 and II are u broken to form ends |004, lub, IIa and IIb, re-

This invention relates to a method and appaspectively. The stencil base I5, as shown in dei tail in Fig. 4, isv provided with a pair of broken concentric rectangular openings I6 and I 1, corresponding in shape to the design of the rectangles Ill and II of Fig. 3. 'Ihis stencil base 5 I5 is adapted to be superimposed on the sheet I2 when the entire stencil is assembled. It will be noted that the openings I6 and I'I are discontinuous and are provided with ends I 6a, ISb

and I'Iz and I'Ib, corresponding to the ends Illa, 10 IUb, IIa and vIIb of the rectangles I0 and II to be formed on the sheet I2. The stencil base is formed ofA some resilient, soft material such as rubber so that it is adapted to be pressed into firm engagement with all parts of the sheet 15 I2 whereby contact of the treating fluidv with the sheet I2 is confined to the portion register'- ing with the openings I6 and I1 of the stencil base.

A stencil cover 20, as shown in detail in Fig. 5, 20 is adapted to be superimposed over the stencil base I5. This stencil cover is provided with a pair of apertures 2| and 22 which are adapted to register with the ends I6a and Ila, respectively, of the openings I6 and I'I inthe stencil 25 base I5 and with a slot 23, which is adapted to span the ends IGb and I 'Ib of said openings `so as to form a connection therebetween -for the purpose to be described.

The stencil cover 20 may be formed of any 30- suitable material. It may, for example, be made of rubber or other soft material similar tothe stencil baseY I5, or it may be made of a hard material and be adapted tobe pressed into firm engagement with the soft material of the stencil 35 base I5. A top plate 30 is provided, as shown in detail in Fig. 6, which lis adapted to engage the entire surface of the stencil cover 20. This top plate 3i!y may be provided with a pair of open- 40 ings 3i and 32- which are adapted to register with the openings 2| and 22 in the stencil cover 2li-andV may be threaded or otherwise adapted to receive the ends of pipas 33 and 34 through which the treating liquid is to be circulated. 45

The assembly is shown more in detail in Fig. 2 as comprising a base plate 40 on which the sheet I2 is positioned. The stencil base I5, stencil cover 20 and top plate 30 are placed in superimposed` relationship on the sheet I2 and the 50 assembly is held under pressure by suitable clamping means. In the embodiment shown this clamping means comprises a frame 4I which is A hinged as at 42 to a `bracket 43 attached to the base plate 40 in any suitable manner as by a hinge 44. The frame 4|v is provided with a pair of ears 45 having a slot 46 therebetween through which a rod 41 extends. The rod 41 is hinged as at 48 to a suitable ear 49 on the base plate A 40 and carries a Wingnut 5Il which engages-the clamping pressure to be applied at -both sides of the frame or other clamping means may be substitute'd therefor. A convenient and compact embodiment has been shown for purposes of illustration.

In the operation of this stencil the parts are first assembled in the manner indicated'in Fig. 2. The treating iiuid may then be applied through, for example, pipe 34. passes through the opening 22 in the stencil -cover and to the end Ila of the opening I1 in the stencil base I5. The fluid then passes around the'rectangular opening I1 to the end I1b thereof and thence it passes through thelopening 23'of the stencil'cover 2I'IA to the end |617l of the opening I6 in the stencil base I5.' The fluid then flows around the opening I6 to the end |6a thereof,

thence upwardly through thev opening 2| in the stencil cover 20 and out through the pipe 33. It will be.` noted thaty the uidthus flows serially throughout'the entire stencil. 1t is to be understood, of course, that the stencil. may be provided with any suitable design and that by a suitable arrangement of the openings 2|, 22 and 23 of the stencil cover,the fluid may be caused to flow serially throughout the stencil regardless of the shape or arrangement ofthe design therein.

It will be noted that only suicient liquid is required to completely ll the stencil openings. Furthermore, circulation may be obtained by continuously applying liquid through the pipe 34 and removing the same through the pipe 33. v -Recirculation can be obtained for conserving the liquid if desired. Furthermore, the liquid may be held under any suitable pressure during its passage through the stencil openings. This continuous circulation of the liquid is desirable in various types of treatment, for example, when using a mixture or a suspension the circulation prevents undesired settling or separation of the materials. The stencil is also adapted for use with articles having a disagreeable odor or emitting a poisonous vapor inasmuch as it is completely closed and there is no danger of the operator coming in contact with either the liquid itself or with the vapors therefrom. The stencil may be used for electroplating by making the plate 20 of the-anode metal and making suitable electrical contact with the base material I2.

The stencil base I is preferably made of soft, resilient material when it is to be used with a hard or rigid sheet I2 in order to ensure that the stencil conform to the surface of the sheet I2 and maintain a liquid tight contact throughout itsarea. It is to be understood of course that a metallic or other rigid stencil could be used if the sheet I2 is made of flexible material.

When the stencil is to be used to apply a design to a plastic composition, the stencil base I5,

stencil cover 20 and top plate 30 may be made of The duid thus applied non-metallic materials. In that event no metal will come in contact with the treating liquid. This is an important feature when certain treating liquids, such as an acid or other substances which readily attack metal are to be used.

Although a particular embodimentof the in-V uid is applied to selected portions of the openings in said base and having additional openings spanning other parts of theopenings in said base to form a continous channel in which the liquid is caused toflow serially. A

2. A stencil for applying a design to a surface,

. comprising a stencil base having a set of disconnected openings therein forming said design, a stencil cover having a pair of openings through .'vwhich liquid is applied to and removed from said openings, said stencil cover having oneA or more additional openings adapted to span the openings in said stencil base so as to form a serial connection thereof topermit the liquid to flow serially through the various openings in said stencil base.

3. A closed stencil, comprising a stencil base having openings therein corresponding to a design to be stenciled, a cover therefor closing the openings in said base, said cover having openings therein forming connecting channels between said first openings to permit the liquid to ow serially therethrough and a top plate closing said last openings in said stencil cover land having a pair of openings through which the liquid is applied to and removed from the openings in said stencil base.

4. A stencil for treating the surface of a plastic composition with a fluid which is corrosive to metal, said stencil comprising a sheet of' rubber having openings therein corresponding to the design to be applied to said surface, a second sheet of rubber adapted to cover said openings, said second sheet having openings formed therein adapted to span the openings in said first sheet so as to form a continuous channel for the passage of saidliquid, and a non-metallic top plate covering said second -sheet and having therein a pair vof openings for applying said liquid to and removing said liquid from the openings in said first sheet.

5. A stencil for applying a design to a surface, said stencil having disconnected channels conforming in shape to said design and open to said surface; and connecting passages out of contact with said surface, each connecting passage joining the ends of a pair of said disconnected channels to form with said channels a continuous closed passage of which said disconnected channels conform to said design, and being adapted to cause the treating -liquid to iiow serially through said channels over the exposed parts of said surface for forming said design.

BERNARD F. W'ALKER. 

